Phys.org news tagged with:excitonhttps://phys.org/
en-usPhys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.Pathway opens to minimize waste in solar energy captureResearchers at the ARC Centre of Excellence in Exciton Science have made an important discovery with significant implications for the future of solar cell material design.https://phys.org/news/2018-01-pathway-minimize-solar-energy-capture.html
Materials Science Mon, 22 Jan 2018 11:00:10 ESTnews435824900Scientists found excitons in nickel oxide for the first timeRussian scientists from Ural Federal University (UrFU), together with their colleagues from Institute of Metal Physics of the Ural Department of Russian Academy of Sciences, have studied fundamental characteristics of nickel oxide nanocrystals and found excitons on the light absorption edge for the first time. An exciton is an electron-hole pair bound with electrostatic coupling that migrates in a crystal and transmits energy within it. The presence of an exciton in this area allows for detailed research of edge parameters in permitted energy bands. This may be useful for the development of next-generation optoelectronic devices. The results of the study were published in Physica B: Physics of Condensed Matter journal.https://phys.org/news/2018-01-scientists-excitons-nickel-oxide.html
Materials Science Mon, 15 Jan 2018 05:26:01 ESTnews435216336Using the dark side of excitons for quantum computingTo build tomorrow's quantum computers, some researchers are turning to dark excitons, which are bound pairs of an electron and the absence of an electron called a hole. As a promising quantum bit, or qubit, it can store information in its spin state, analogous to how a regular, classical bit stores information in its off or on state. But one problem is that dark excitons do not emit light, making it hard to determine their spins and use them for quantum information processing.https://phys.org/news/2017-12-dark-side-excitons-quantum.html
Optics & Photonics Wed, 20 Dec 2017 09:19:16 ESTnews432983946Spontaneous Bose-Einstein condensation of excitonsExcitons are pairs of electrons and holes inside a solid material that together behave like a single particle. It has long been suspected that when many such excitons exist in the same piece of matter, they can form a single giant quantum state called a Bose-Einstein condensate – the same process which is responsible for a metal losing all its electrical resistance when it becomes a superconductor, for example. However, actually proving that Bose-Einstein condensation of excitons occurs in any real material has been a challenge for physicists for decades. An experiment done at the University of Illinois at Urbana-Champaign, carried out in collaboration with UvA-Institute of Physics researcher Jasper van Wezel, has uncovered evidence that this elusive state of matter really does exist. Their results were published in Science this week.https://phys.org/news/2017-12-spontaneous-bose-einstein-condensation-excitons.html
Quantum Physics Fri, 08 Dec 2017 10:14:11 ESTnews431950430The exciting future of light energyIn a world of growing energy needs, and a global imperative to halt carbon emissions, a tiny 'quasiparticle' called an exciton could provide the answer to our problems.https://phys.org/news/2017-06-future-energy.html
General Physics Mon, 19 Jun 2017 08:59:10 ESTnews417081531Shedding light on the absorption of light by titanium dioxideTitanium dioxide (TiO2) is one of the most promising materials for photovoltaics and photocatalysis nowadays. This material appears in different crystalline forms, but the most attractive one for applications is called "anatase". Despite decades of studies on the conversion of the absorbed light into electrical charges in anatase TiO2, the very nature of its fundamental electronic and optical properties was still unknown. EPFL scientists, with national and international partners, have now shed light onto the problem by a combination of cutting-edge steady-state and ultrafast spectroscopic techniques, as well as theoretical calculations. The work is published in Nature Communications.https://phys.org/news/2017-04-absorption-titanium-dioxide.html
Condensed Matter Thu, 13 Apr 2017 05:00:01 ESTnews411274441Entanglement at heart of '2-for-1' fission in next-generation solar cellsAn international team of scientists have observed how a mysterious quantum phenomenon in organic molecules takes place in real time, which could aid in the development of highly efficient solar cells.https://phys.org/news/2015-10-entanglement-heart-for-fission-next-generation.html
Condensed Matter Mon, 26 Oct 2015 12:00:04 ESTnews365064406Exciting breakthrough in 2-D lasers: Researchers demonstrate atomically thin excitonic laserAn important step towards next-generation ultra-compact photonic and optoelectronic devices has been taken with the realization of a two-dimensional excitonic laser. Scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) embedded a monolayer of tungsten disulfide into a special microdisk resonator to achieve bright excitonic lasing at visible light wavelengths.https://phys.org/news/2015-10-breakthrough-d-lasers-atomically-thin.html
Optics & Photonics Tue, 20 Oct 2015 12:57:34 ESTnews364564642Researchers use engineered viruses to provide quantum-based enhancement of energy transportNature has had billions of years to perfect photosynthesis, which directly or indirectly supports virtually all life on Earth. In that time, the process has achieved almost 100 percent efficiency in transporting the energy of sunlight from receptors to reaction centers where it can be harnessed—a performance vastly better than even the best solar cells.https://phys.org/news/2015-10-viruses-quantum-based-energy.html
General Physics Thu, 15 Oct 2015 06:48:28 ESTnews364110486Researchers detect how light excites electrons in metalResearchers have observed, in metals for the first time, transient excitons – the primary response of free electrons to light. Here, the researchers discovered that the surface electrons of silver crystals can maintain the excitonic state more than 100 times longer than for the bulk metal, enabling the excitons to be experimentally visualized by a newly developed multidimensional coherent spectroscopic technique.https://phys.org/news/2015-06-electrons-metal.html
General Physics Mon, 01 Jun 2015 09:30:01 ESTnews352366816Theorists find a new way to improve efficiency of solar cells by overcoming exciton 'traps'A major limitation in the performance of solar cells happens within the photovoltaic material itself: When photons strike the molecules of a solar cell, they transfer their energy, producing quasi-particles called excitons—an energized state of molecules. That energized state can hop from one molecule to the next until it's transferred to electrons in a wire, which can light up a bulb or turn a motor.https://phys.org/news/2014-09-theorists-efficiency-solar-cells-exciton.html
Condensed Matter Sun, 21 Sep 2014 13:00:03 ESTnews330522536Excitonic dark states shed light on TMDC atomic layers(Phys.org) —A team of Berkeley Lab researchers believes it has uncovered the secret behind the unusual optoelectronic properties of single atomic layers of transition metal dichalcogenide (TMDC) materials, the two-dimensional semiconductors that hold great promise for nanoelectronic and photonic applications.https://phys.org/news/2014-09-excitonic-dark-states-tmdc-atomic.html
Nanophysics Thu, 11 Sep 2014 07:10:16 ESTnews329638207Solar energy gets a boost: Work on 'singlet fission' can increase solar cell efficiency by as much as 30 percentA perspective article published last month by University of California, Riverside chemists in the Journal of Physical Chemistry Letters was selected as an Editors Choice—an honor only a handful of research papers receive. The perspective reviews the chemists' work on "singlet fission," a process in which a single photon generates a pair of excited states. This 1->2 conversion process, as it is known, has the potential to boost solar cell efficiency by as much as 30 percent.https://phys.org/news/2014-07-solar-energy-boost-singlet-fission.html
Materials Science Tue, 08 Jul 2014 13:37:00 ESTnews324045408Getting more electricity out of solar cells(Phys.org) —When sunlight shines on today's solar cells, much of the incoming energy is given off as waste heat rather than electrical current. In a few materials, however, extra energy produces extra electrons—behavior that could significantly increase solar-cell efficiency.https://phys.org/news/2014-05-electricity-solar-cells.html
Materials Science Wed, 07 May 2014 16:34:12 ESTnews318699227First direct observations of excitons in motion achievedA quasiparticle called an exciton—responsible for the transfer of energy within devices such as solar cells, LEDs, and semiconductor circuits—has been understood theoretically for decades. But exciton movement within materials has never been directly observed.https://phys.org/news/2014-04-excitons-motion.html
Nanophysics Wed, 16 Apr 2014 05:00:02 ESTnews316800712Quasi-particle swap between graphene layersBelgian scientists have used a particle physics theory to describe the behaviour of particle-like entities, referred to as excitons, in two layers of graphene, a one-carbon-atom-thick honeycomb crystal. In a paper published in European Physical Journal B, Michael Sarrazin from the University of Namur, and Fabrice Petit from the Belgian Ceramic Research Centre in Mons, studied the behaviour of excitons in a bilayer of graphene through an analogy with excitons evolving in two abstract parallel worlds, described with equations typically used in high-energy particle physics.https://phys.org/news/2014-02-quasi-particle-swap-graphene-layers.html
Nanophysics Mon, 03 Feb 2014 11:24:52 ESTnews310649084Unlocking nature's quantum engineering for efficient solar energy(Phys.org)—Quantum scale photosynthesis in biological systems which inhabit extreme environments could hold key to new designs for solar energy and nanoscale devices. Certain biological systems living in low light environments have unique protein structures for photosynthesis that use quantum dynamics to convert 100% of absorbed light into electrical charge, displaying astonishing efficiency that could lead to new understanding of renewable solar energy, suggests research published today in the journal Nature Physics.https://phys.org/news/2013-01-nature-quantum-efficient-solar-energy.html
Quantum Physics Mon, 07 Jan 2013 06:39:35 ESTnews276763164Advances in the understanding of how carbon nanotubes move charges created by light(Phys.org)—A LANL team and collaborators have made advances in the understanding of how carbon nanotubes move charges created by light. The research has applications for cheap, all-carbon-based photovoltaics and light detection elements. Their work measures exciton transport (excitons are small packets of energy made up of positive and negative charges) in carbon nanotubes at room temperature in a colloidal environment. A colloid is a substance that is evenly distributed throughout another substance, generally with particles that are between 1 and 1,000 nanometers in size. The nature of the colloidal environment influences the transport of charge-neutral excitons along the backbone of a carbon nanotube.https://phys.org/news/2012-11-advances-carbon-nanotubes.html
Nanophysics Mon, 12 Nov 2012 07:25:13 ESTnews271927501Excitons: Exotic particles, chilled and trapped, form giant matter wavePhysicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave.https://phys.org/news/2012-05-exotic-particles-chilled-giant.html
General Physics Thu, 24 May 2012 12:07:27 ESTnews257080023Faster colloidal fluorescence emitters: Nanoplatelets(PhysOrg.com) -- Significant advances in the application of colloidal structures as light emitters and lasers may soon be realized following the discovery of very fast fluorescence emission rates in colloidal nanoplatelets. These nanoplatelets combine the best characteristics of two domains: the wide tunability of the absorption and photoluminescence of nanocrystals and the short decay time of excitons in quantum wells. This discovery, which was announced by scientists at the Naval Research Laboratory and Laboratoire de Physique et d'Etude des Mat&#233;iaux, UMR8213 du CNRS, ESPCI, suggests that the nanoplatelets are an important, novel material for constructing tunable light-emitting diodes, low-threshold lasers, and photo-voltaic solar cells. The complete findings of the study are published on line in the October 23, 2011, issue of the journal Nature Materials.https://phys.org/news/2011-12-faster-colloidal-fluorescence-emitters-nanoplatelets.html
Nanophysics Fri, 09 Dec 2011 07:20:01 ESTnews242635325Researchers discover technique to improve solar cell technologyA multi-disciplinary team of scientists at the Naval Research Laboratory has discovered a way to tailor nanostructures that could result in low-cost, high efficiency solar cells. The research appears in the August 10, 2011 issue of the journal Nano Letters.https://phys.org/news/2011-10-technique-solar-cell-technology.html
Nanophysics Wed, 12 Oct 2011 10:27:31 ESTnews237634040Physicists take inspiration from spilled milk(PhysOrg.com) -- Two Lehigh physicists have developed an imaging technique that makes it possible to directly observe light-emitting excitons as they diffuse in a new material that is being explored for its extraordinary electronic properties. Called rubrene, it is one of a new generation of single-crystal organic semiconductors.https://phys.org/news/2011-08-taking-inspiration-from-spilled-milk.html
General Physics Fri, 12 Aug 2011 09:00:35 ESTnews232358416Lighten up: Polaritons with tunable photon-exciton coherence(PhysOrg.com) -- Of the many exotic and counterintuitive aspects of particle and quantum physics, exciton and polariton quasiparticles are among the most interesting. An exciton forms when a photon is absorbed by a semiconductor as a Coulomb force-bound state of a (negatively-charged) electron and a (positively-charged) hole; this particle pair can be seen as an elementary excitation of condensed matter able to transport energy without the transfer of net electric charge, and moreover has size- and shape-dependent optoelectronic properties. A polariton forms due to strong coupling of a photon with an excitation of a material &#150; and among the several types of polaritons, an exciton-polariton is a composite photonic-electronic quasiparticle resulting from coupling of visible light with matter in the form of an exciton. At the same time, the difficulty of achieving increased light-matter coupling strengths has limited the development of applications operating at, for example, higher temperatures and lower power. Recently, however, researchers produced light-matter coupling strengths in nanoscale materials at much higher levels than was previously thought possible in their bulk counterparts. https://phys.org/news/2011-06-polaritons-tunable-photon-exciton-coherence.html
Optics & Photonics Tue, 14 Jun 2011 10:15:28 ESTnews227265287Packing electrons in a nano box: Control of many-Body correlation by quantum confinementA team headed by Dr. Takashi Kuroda, Senior Researcher, and Dr. Marco Abbarchi, Researcher, of the Quantum Dot Research Center, National Institute for Materials Science, in joint research with Hokkaido University, succeeded in controlling the few-particle quantum state of a semiconductor quantum dot, and changing its correlation energies. This research achievement will make it possible to develop semiconductor non-linear devices which enable stable drive with low power consumption.https://phys.org/news/2010-12-electrons-nano-many-body-quantum-confinement.html
Nanophysics Fri, 24 Dec 2010 09:50:11 ESTnews212406590Light touch brightens nanotubes (w/ Video)(PhysOrg.com) -- Rice University researchers have discovered a simple way to make carbon nanotubes shine brighter.https://phys.org/news/2010-12-brightens-nanotubes-video.html
Nanomaterials Thu, 02 Dec 2010 14:52:53 ESTnews210523952Discovery paves way for development of efficient, inexpensive plastic solar cellsPhysicists at Rutgers University have discovered new properties in a material that could result in efficient and inexpensive plastic solar cells for pollution-free electricity production.https://phys.org/news/2010-10-discovery-paves-efficient-inexpensive-plastic.html
Nanomaterials Sun, 10 Oct 2010 13:26:05 ESTnews205935947Discovery brings new type of fast computers closer to realityPhysicists at UC San Diego have successfully created speedy integrated circuits with particles called "excitons" that operate at commercially cold temperatures, bringing the possibility of a new type of extremely fast computer based on excitons closer to reality.https://phys.org/news/2009-09-discovery-fast-closer-reality.html
Optics & Photonics Sun, 27 Sep 2009 14:36:05 ESTnews173280934Light sensor breakthrough could enhance digital camerasNew research by a team of University of Toronto scientists could lead to substantial advancements in the performance of a variety of electronic devices including digital cameras.https://phys.org/news/2009-06-sensor-breakthrough-digital-cameras.html
Engineering Thu, 18 Jun 2009 14:40:02 ESTnews164553830Quantum doughnuts slow and freeze light at will: 'fast computing & slow glass'(PhysOrg.com) -- Research led by the University of Warwick has found a way to use doughnuts shaped by-products of quantum dots to slow and even freeze light, opening up a wide range of possibilities from reliable and effective light based computing to the possibility of "slow glass".https://phys.org/news/2009-03-quantum-doughnuts-fast-glass.html
General Physics Mon, 09 Mar 2009 15:14:21 ESTnews155830401